Have you looked into a potential different structure with instead of a seller note, structure it through equity in an LLC partnership? 

However I'm wondering what is a good roi and structure. 

I'm currently spending time learning as much as I can from various resources including books here on BP, accumulating capital and structuring my strategy. 

I have read many articles on the types of real estate investment strategies like wholesaling, buy and flip (and buy and hold), structuring deals for no money down seller financing and even investing in notes! 

Were you successful in setting up this structure and keeping the loan without triggering a due on sale clause?

Yes, you can; this strategy is called pooling and it also adds a tremendous tax advantage You'll just need to make sure the entity pulling and disbursing the capital is structured correctly for its maximum benefit  

Caught the flag on the first sentence "given the loan terms verbally" - Pretty much all the "reputable" DSCR Lenders will give out a detailed term sheet / pre-approval letter / LOI (many different names but same thing) outlining terms and approvals early on in the process - the good news is that if you haven't closed yet you can still switch lenders and see if you can secure your original terms - also good news is that the appraisal, while likely ordered by the lender or broker is in your name and your property, so you can likely transfer it to the new lender

These loans come from professional private lenders, are more structured, and have higher interest rates (8% to 15%) with shorter terms (6 months to 3 years).

I am just curious how most structure their payment process when receiving and paying rental payments, vender payments, etc.

It can be a great alternative to traditional bank loans, offering flexibility in terms of both loan structure and timelines.